A 68-year-old man with type 2 diabetes mellitus presents to the hospital with a 3-day history of fever, productive cough with purulent sputum, and progressive dyspnea. He was hospitalized 2 weeks ago for acute coronary syndrome and received empiric antibiotics during that admission. Current vital signs: temperature 39.2°C, blood pressure 132/78 mmHg, heart rate 108/min, respiratory rate 24/min, oxygen saturation 93% on room air. Physical examination reveals crackles in the right lower lobe. Chest X-ray shows a right lower lobe consolidation. Laboratory findings: WBC 15,400/μL, creatinine 1.1 mg/dL, blood glucose 280 mg/dL. Blood cultures and sputum culture both grow Klebsiella pneumoniae that is resistant to ceftriaxone and cefepime but susceptible to carbapenems and fluoroquinolones. Which of the following is the most appropriate empiric antibiotic therapy for this patient?

1. A)Ceftriaxone 2 g IV every 12 hours
2. B)Levofloxacin 750 mg IV daily
3. C)Piperacillin-tazobactam 4.5 g IV every 6 hours
4. D)Ampicillin-sulbactam 3 g IV every 6 hours
5. E)Meropenem 1 g IV every 8 hoursGABARITO